I feel obligated to post how I managed to get both my roommate and myself connected to C&C3 online at the same time under the same router, because I haven't seen the solution anywhere else. Hopefully, Google will do it's job and direct anybody with a similar problem here.
The situation: Both my roommate and I (running Windows Vista) want to play C&C3 online at the same time, both connected via wireless to the Linksys WRT54G router.

Normally, getting a game to work online involves opening a port, so the router can know to whom to direct network traffic. C&C: Generals was like this. No biggie! Open up two different ports: one pointing to me, and one pointing to him... and then change the setting in the game.
C&C3 posses a problem in that it requires a LARGE amount of ports open to work that you CANNOT change from within the game. You can set a single port to watch, but the game itself requires a large range to work.
The solution: Port triggering. Port triggering is like port forwarding that activates when a client starts talking to a specific port. This allows selective port forwarding as each client needs it and thus, we both have access to the full range of ports needed to run the game. The probability of collisions is low, given the large range. So the settings look like this:
- Set ports 2049 through 29910 to be triggering ports
- Set any port NOT in that range to be forwarded to a specific player on the network. Do this for all players.
- Then, in the Options->Network tab in the game, type in your port that you forwarded in the previous step.
And you're done! If anybody else tries this, let me know, as I'm curious as to whether it really works... or it was just a fluke that it worked for us.
There is a known issue that if one of us hosts an online game, and the other joins AND somebody outside the network joins the game, both of our games (and the router!) crash when the game is loading. However, playing 1v1 online against my roommate works, and playing in different games online at the same times work, and hosting games works.












